Overpeck’s Enigmatic Tuq(?)

In fairness to Kaufman, he and his students actually did useful field work. Elsewhere I’ve noted that their MSc theses contain many helpful details on the Alaskan lakes. The situation is entirely different with the Greenland lakes, where Jonathan Overpeck was the point man for the ARCUS2k lake project collection.

Kaufman et al 2009 contains one sediment record from Greenland – SFL4-1 organic material (OM%), published (and archived) in 1999 by Willemse (pdfdata ). The most recent sediment in this series is dated to 1938; it is ascribed approximately decadal resolution.

Together with the three truncated Finnish proxies (see upside-down Mann problem), the lack of closing data for these records resulted in short-segmenting of the latter portion of the standardization period (something that Hu has expressed concern about.) It’s hard to see that the upside-down truncated Finnish proxies add useful information to this recon; the old Greenland OM% series is the only other series with a short modern period.

The purpose of Kaufman’s program was to triple the number of new proxies – so why didn’t they get any new data for Greenland? Why did he use the tired old SFL4-1 series? I can’t imagine that Kaufman was thrilled to use this thing.

It wasn’t for lack of funding of the Greenland data. Overpeck got about 50% of the amount that Kaufman got. (Ammann actually got more than Kaufman – I wonder what Kaufman got out of Ammann: again, I can’t imagine that he was thrilled to have to recycle the 5600-3600 BP GCM run, after Ammann and associates got $261,000 to model runs for him.)

Unlike Kaufman’s grant sheet where several publications are listed, Overpeck’s grant sheet does not show any publications (Overpeck is listed as a Kaufman 2009 coauthor and I suppose that will ultimately accrue on this grant sheet as well as the others.)

In the original listing of 30 NSF sites, the Greenland sites that seem to be Overpeck’s responsibility are Sved Lake and Tuqtotog Lake.

Greenland (Anderson)
-6 records from west Greenland
-He wonders what the controls are on the proxies.
-Argues that the records presented are oversimplified.

Doubtless CA readers are also wondering “what the controls are on the proxies”. The attendance includes two Andersons (J and L). Neither Overpeck nor Francis were there.

None of the PI meeting minutes make any reference to the inclusion of the (ancient) SFL4-1 OM% series as a Greenland sediment representative. According to the minutes, Overpeck;s data was nearly ready, but it’s fallen off the radar. Unfortunately, we have previously had unfortunate precedents for non-archiving of data in climate science, e.g. Jacoby:

If we get a good climatic story from a chronology, we write a paper using it. That is our funded mission. It does not make sense to expend efforts on marginal or poor data and it is a waste of funding agency and taxpayer dollars. The rejected data are set aside and not archived.

While one always hopes that things improve, the failure to provide any accounting for the missing Overpeck data is not very encouraging. And it’s not as though the PI were unprepared for scrutiny. After all, the Iceland meeting minutes say:

We need to be very careful that all data included in the synthesis are publicly available, and preferably peer-reviewed. We will be SCRUTINIZED. Ideally as many *published* records as possible. We may be a lightning rod – and therefore need to be extremely careful to document our decisions and be ready to publicly defend them.

Overpeck seems to have been paid in full for his data. Time for Overpeck to archive it. Perhaps Kaufman will endorse this request.

I found this more interesting – is this acknowledgment of a medieval warm period??? And note the GCM reference.

Priority will be on the 400-year-long interval between 850
and 1250 AD. This period is probably the longest interval of relative warmth during the last 2
kyr and is bounded by pronounced cooling events, which might help to synchronize our records;
it will also be a focus of our GCM experiments. Please make a strong effort to complete
geochronological and proxy analyses at the highest-possible resolution over this interval of your
lake records during the coming year.